1. Field
The field relates to a flat panel display panel sealing device and a method of using the device. More particularly, the field relates to a flat display panel sealing device that seals a rear substrate and a front substrate that receives radiated light at a cell sealant between the rear and front substrates while the two substrates are pressed together.
2. Description of the Related Technology
A flat panel display panel includes, for example, a liquid crystal display (LCD), a plasma display panel (PDP), and an organic light emitting diode (OLED) display. For convenience, the OLED display will be described.
The OLED display includes a plurality of organic light emitting diodes (OLEDs) each of which includes a hole injection electrode, an organic emission layer, and an electron injection electrode, and light is emitted by energy that is generated when an exciton that is generated by coupling of electrons and holes falls from an excited state to a ground state within the organic emission layer.
The OLED display arranges subpixels in a matrix format in a display area, and the subpixel includes an OLED and a driving circuit unit. The driving circuit unit includes a switching transistor, a driving transistor, and a storage capacitor.
The OLED display is formed by forming subpixels at a rear substrate and sealing the sear substrate to a front substrate. A sealing method of the OLED display includes a laser sealing method.
For example, according to the laser sealing method, a glass frit is arranged between the rear substrate and the front substrate at an edge of the display area, and the rear substrate and the front substrate are sealed by heating the glass frit with a laser beam.
The laser sealing method using the glass frit may generate a sealing failure if the rear substrate and the front substrate are not tightly attached to the glass frit.
In some embodiments, the OLED display may be individually manufactured, or, alternatively a plurality of OLED displays may be manufactured together for productivity improvement.
In a substrate array, the rear substrate and the front substrates are bonded to each other by an edge sealant provided at an edge between the two substrates. The plurality of unit cells are isolated by the edge sealants around each unit cell.
The laser sealing method can be further applied to seal the rear substrate and the front substrate by heating the cell sealant of the substrate array that is bonded by the edge sealant.
For example, according to a vacuum method, the rear substrate and the front substrate are bonded under vacuum, the vacuum condition is changed to an atmosphere condition and the cell sealant is attached to the front substrate by using an internal and external pressure difference of the rear and front substrates, and the two substrates are sealed by heating the cell sealant with a laser beam.
When the vacuum is insufficient, that is, when internal pressure is not low enough compared to external pressure, the rear substrate and the front substrate are not securely attached. As a result the substrates can separate.
Once the rear substrate and the front substrate are bonded, a cavity may be formed in one substrate in order to ease the increase of the internal pressure with an increase of internal volume. In this case, the cell sealant may be separated due to the internal volume of the substrates, alignment of the cell sealant, and location of an edge sealant.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.